I was building a Playwright suite against a Phoenix LiveView app for the first time. Tests ran fine in isolation. Overnight, the full suite timed out across the board. Every failure was in a navigation.
What Playwright Waits For by Default
When you call page.goto() or trigger a navigation through a click, Playwright waits for the load event before moving on. That assumes a traditional request/response cycle: the browser makes a request, the server returns a full HTML document, the browser fires load when everything is done.
LiveView doesn't do that. Navigation happens over a persistent WebSocket connection. The URL changes, the page updates, but there's no new document and no load event in the way Playwright expects. So Playwright waits, hits the timeout, and the test fails.
The Fix: waitUntil commit
